Fatigue behaviour of additively-manufactured metallic parts

An overview on recent research efforts is presented to obtain an understanding on the fatigue behaviour and failure mechanisms of metallic parts fabricated via powder-based additive manufacturing (AM) processes, including direct energy deposition (DED) and powder bed fusion (PBF) methods, utilizing either laser or electron beam as an energy source. Some challenges inherent to characterizing the mechanical behaviour of AM metals under cyclic loading are discussed, with emphasis on the effects of residual stresses on their fatigue resistance. In addition, an aspect pertaining to the structural integrity of AM parts relating to their fatigue behaviour at very high cycles is presented and compared with those of the conventionally-manufactured counterparts.